Berwick Computer Services are offering a "No Fix, No Fee" offer, which is as follows :

If we come to your premises or if you bring a machine to us to be fixed, and we cannot fix the problem, then we will not charge you for it, as long as we have taken less than one hour to come to this conclusion. If it has taken more than an hour, then you would only pay for the time after this, we would not charge you for the first hour. Either way, you save money. This offer does not include any parts we may have to buy to try and fix the problem, you are still liable for the payment for the parts.